9×1.5″ C24 Treated Timber Rough Sawn (225×35 mm) – 3 m
€20.40
In stock
Your security and privacy are at the heart of everything we do. Every purchase you make is protected by industry‑leading safeguards designed to keep your personal and payment information safe.
Secure Payments
Pay with complete confidence using our trusted, fully protected payment methods. Your card details remain secure, uncompromised, and handled with strict care.
All sensitive data is encrypted from end to end, and we never sell or share your card information, ever.
Payment Methods
We accept credit and debit cards from most major credit issuers. Your card can be saved for future purchases and you can remove or edit the card information at any time. For questions regarding your transactions on our site, please consult your card-issuing bank.
We deliver across all four zones defined below.
Quantity savings
Enjoy automatic discounts as soon as your basket qualifies—no codes, no hassle.
Buy 25–49 units
Get 3% off your entire qualifying product order.
Buy 50+ units
Get 5% off your entire qualifying product order.
How it works
Your discount is applied automatically at checkout based on the total quantity of eligible items in your basket. The more you buy, the more you save—simple, transparent, and designed to reward our customers.
Product specification
- Length
- 3000 mm
- Width
- 225 mm
- Thickness
- 35 mm
- Material
- Timber
- Wood Type
- Softwood
Treated C24 Timber
9×1.5 treated whitewood, 225 by 35 mm, is the deepest light treated section: external stair strings, deep trimmers over damp voids, and tall framing in outbuildings where depth is needed but weight is not welcome. Strength-graded to C24 and kiln-dried below 22% moisture content before treatment. Lengths run from 3 m to 5.4 m. Stocked in our warehouse for delivery across Ireland.
Why treated C24?
An external stair string is the clearest case for this size. It is cut, notched and drilled all over, it sits outdoors, and every notch is a trap for water. Treatment protects the bulk of the section, and because the preservative is pressure driven the timber remaining behind each notch is protected too, not just the surface you can see.
Installation guidance
Set out a string from a full-size rod and keep at least 65 mm of uncut timber behind the deepest notch. Treat every cut face as you make it, and pay particular attention to the horizontal tread seats where water will stand. Support the string at both ends clear of the ground on a galvanised shoe rather than bedding it into concrete.
Finishing & maintenance
An external stair should be stained or oiled once dry, both for appearance and to slow surface checking. Re-treat cut faces every few years where they are exposed. For an internal stair or trimmer, use 9×1.5 C24 timber rough sawn. Browse all C24 treated timber sizes, from light boards to deep joists. To compare sawn and treated sizes side by side, see our construction timber page.